Inventories - Summary of Inventories (Detail) - USD ($) $ in Thousands	Jul. 04, 2020	Dec. 28, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 48,998	$ 41,255
Work-in-progress	2,270	2,337
Finished goods	292	259
Inventories	$ 51,560	$ 43,851

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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